Business reporter

UNITHOLDERS in BrisConnections have been warned that their equity is at risk after the group's bankers appointed insolvency experts PPB Advisory to review the troubled toll road builder's business on Friday.

Between them, Macquarie Group and Deutsche Bank own 79 per cent of units in BrisConnections, which built and operates Brisbane's $4.8 billion Airport Link. BrisConnections said that PPB's review would ''look at current and anticipated traffic volumes, revenue, costs, forecast liquidity and BrisConnections' capital structure''.

''It is possible that actions may arise as a result of this review which may have adverse implications on the future value of equity,'' it told the market.

The project is one of a group of private sector toll roads, including Sydney's Cross City Tunnel, to run into financial trouble after construction delays, cost overruns and lower traffic than expected.

Macquarie and Deutsche took out retail unitholders after BrisConnections first ran into trouble in 2009, taking on their obligation to pay an additional $2 per $1 security.

Macquarie owns 45 per cent of units, with Deutsche Bank holding 33 per cent and the state government's Queensland Investment Corporation holding 8.28 per cent.

Traffic on the Airport Link fell from 74,500 trips a day in September to 66,200 trips a day in October. This is about 40 per cent of the number forecast by BrisConnections when it was preparing to float in 2008.

BrisConnections last week unveiled an operating loss for the first three months of the financial

year of $55.8 million, down from $82 million the previous quarter.

The link has also cost its builder, Leighton, more than $1 billion in writedowns and direct losses.

Units in BrisConnections were originally sold in investors in its $1.2 billion float for $1 up front, with $2 more to pay in two instalments of $1 each.

The trust came close to collapse following the global financial crisis, when it became apparent many retail unitholders could not or would not meet a call for additional capital.

Units dropped to 0.1¢ in April 2009 as raider Nicholas Bolton built up a stake in BrisConnections that retail investors hoped would be voted to wind up the trust and extinguish their debt.

However, Mr Bolton sold voting rights in his units to Leighton, which voted them against a wind-up.

Many retail unitholders subsequently defaulted on their obligation to pay the first $1 call, forcing Macquarie and Deutsche to take on the units under an underwriting agreement.